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Security Tool
Port Scanner
Scan any IP address or domain for open ports. Check common ports or specify a custom range to identify running services and potential vulnerabilities.
How to Use
Use Port Scanner in 4 Steps
01
Enter host
Type the IP address or domain name you want to scan.
02
Select ports
Choose to scan common ports or enter a custom range.
03
Start scan
Click scan to initiate connection attempts to the target.
04
Review results
See which ports are open, closed, or filtered.
What is a Port Scanner?
A port scanner is an application designed to probe a server or host for open ports. Such an application may be used by administrators to verify security policies of their networks and by attackers to identify network services running on a host and exploit vulnerabilities.
How does it work?
A port scan consists of sending a message to each port, one at a time. The kind of response received indicates whether the port is used and can therefore be probed further for weakness.
Common Ports
- 21 (FTP): File Transfer Protocol
- 22 (SSH): Secure Shell
- 25 (SMTP): Simple Mail Transfer Protocol
- 53 (DNS): Domain Name System
- 80 (HTTP): Hypertext Transfer Protocol
- 443 (HTTPS): HTTP Secure
- 3306 (MySQL): MySQL Database System
Frequently Asked Questions
What is the difference between closed and filtered ports?
Closed ports respond that no service is listening. Filtered ports are usually blocked by firewall or network policy.
Is port scanning legal?
Scan only systems you own or are explicitly authorized to test.
Why are results different from another scanner?
Scan origin, protocol method, timing, and edge firewall behavior can produce different outcomes.
Port States
OpenAccepting connections
ClosedRejecting connections
FilteredBlocked by firewall